Fernando Ortenzi

Test of blends of hydrogen and natural gas in a light duty vehicle

Hydrogen-enriched combustion has been studied by several institutions and companies over the last three decades. The purpose of adding hydrogen to conventional fuels is to extend the lean limit of combustion because hydrogen improves flame stability and allows a lower temperature combustion. Even with stoichiometric mixture, HCNG advantages had been demonstrated, since blends determine a reduction of noxious emissions. In the framework of an EU project called BONG-HY, bench tests with HCNG on a natural gas vehicle had been carried on at ENEA. Results of lab tests show a fair improvement of the efficiency and CO2 emissions as well as an overall improvement regarding local pollutants.

Experimental Measurement of the Environmental Impact of a Euro IV Vehicle in its Urban Use

Passenger vehicles are one of the most significant source of pollution in the cities. The emissions production of a vehicle is strictly dependent on how the vehicle is used. This paper has the objective to characterize a Euro IV vehicle so to understand in depth the behavior in its real usage on road in terms of fuel consumption and emissions.

Experimental analysis of an electric minibus with small battery and fast charge policy

The lead-acid battery of an electric minibus has been replaced with a smaller size lithium-ion battery system consisting of standard 12 V modules and a hierarchical battery management system. The minibus has experimentally been tested to show that the reduced battery capacity, which also cuts costs, does not affect the daily operational mission. This is assuming that the driving phases are alternated with fast charging periods. Experiments show that fast charging of 8 min guarantees up to 1 h of operation.

Quantitative Analysis of Efficiency Improvement of a Propulsion Drive by Using SiC Devices: A Case of Study

One of the emerging research topics in the propulsion drive of the electric vehicles is the improvement in the efficiency of its component parts, namely, the propulsion motor and the associated inverter. This paper is focused on the efficiency of the inverter and analyzes the improvement that follows from the replacement of the silicon (Si) IGBT devices with silicon carbide (SiC) MOSFETs. To this end, the paper starts by deriving the voltage-current solicitations of the inverter over the working torque-speed plane of the propulsion motor. Then, a proper model of the power losses in the inverter over a supply period of the motor is formulated for the two types of device, including the integrated freewheeling diode. By putting together the voltage-current solicitations and the device power losses, the efficiency maps of the Si IGBT and SiC MOSFET inverters are calculated and compared over the torque-speed plane. The results for the Si IGBT inverter are supported by measurements executed on a marketed C-segment compact electric car, while the SiC MOSFET loss model is validated by an on-purpose built test bench. Finally, the overall efficiency of the propulsion drive is calculated by accounting for the motor efficiency. Main outcomes of the paper is a quantitative evaluation of both the improvement in the efficiency achievable with the SiC MOSFETs and the ensuing increase in the electric car range.

Enriched Methane for City Public Transport Buses

Hydrogen is seen as an alternative strategy to overcome the energy dependence on fossil fuels. The epochal change recognized by the “hydrogen revolution” has not yet occurred; however, many efforts toward carbon-free energy development have been made. In the world of transportation, hydrogen as a fuel, has demonstrated reduction of pollutant emissions and better energy efficiency. Although low temperature fuel cells (FC) allow using FC generators on board of vehicles, there are still some open issues regarding FC generator durability and hydrogen storage. Furthermore, some manufacturers have already designed and produced vehicles powered by internal combustion engines fueled with hydrogen. As a matter of fact for both technologies, the major obstacle consists in the lack of a hydrogen distribution network. While awaiting for satisfactory solutions to the large availability of hydrogen at gas stations an intermediate step toward a carbon- free mobility is achievable with the mixtures of hydrogen and methane. These blends represent an interesting application to take advantage of conventional combustion engines and to promote the transition toward hydrogen mobility. The higher combustion characteristics of hydrogen result in a higher combustion efficiency that is able to reduce energy consumption and CO2 emission due to the lower presence of carbon in the mixture. The Mhybus project demonstrates the feasibility of using hydrogen-methane blends as fuel in public transportation and highlights energy and environmental advantages.